The overall objectives are: 1) to conduct feasibility studies at the Georgia Retardation Center to determine whether the computer-based language-training system and techniques of training developed through research with chimpanzee subjects at the Yerkes Primate Center might facilitate the language acquisition of nonverbal mentally retarded children and elucidate certain problems of language learning by them and 2) to assess the potential value of the chimpanzee as an animal model for research of a linguistic type which bears upon the acquisition of initial language skills that cannot be conducted with human children because of ethical constraints. Work with the mentally retarded children will concentrate upon language acquisition and use in relation to environmental change and curiosity; in relation to problem-solving activities and the enhancement of social commerce; and in relation to the management of behavioral management problems. Work with the chimpanzee projects will concentrate upon the use of learned symbols as representations of referents, the boundaries of concepts which entail use of word-lexigrams, the mastery of words for actions and names for animates, the use of line-drawings as representations, and the development of subject-computer interactive instructional programs for the mastery and use of language-relevant-skills.